13081638 has 16 divisors (see below), whose sum is σ = 26208000. Its totient is φ = 4353096.

The previous prime is 13081631. The next prime is 13081667. The reversal of 13081638 is 83618031.

13081638 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is a super-2 number, since 2×13081638² = 342258505526088, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13081631) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2863 + ... + 5861.

It is an arithmetic number, because the mean of its divisors is an integer number (1638000).

Almost surely, 2^13081638 is an apocalyptic number.

13081638 is an abundant number, since it is smaller than the sum of its proper divisors (13126362).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

13081638 is a wasteful number, since it uses less digits than its factorization.

13081638 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3731.

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 13081638 is about 3616.8547109332. The cubic root of 13081638 is about 235.6246427067.

Adding to 13081638 its reverse (83618031), we get a palindrome (96699669).

The spelling of 13081638 in words is "thirteen million, eighty-one thousand, six hundred thirty-eight".